rocking along!

10/2

after adding a new stem and bars, when I apply the front brake the forks judder and rock back and forth, how do i remedy this? its an A-head fitting. cheers

banana_man

Presumably by changing your stem you have made a gap between the bottom of the stem and the spacers that sit on the steerer tube. If this is the case then your forks will judder under braking or harsh pedalling because the steerer tube is not an exact fit in the headtube of the frame.

Anyway... if your stem is pointing downwards it may be hitting the spacers and leaving the aforementioned gap, so you could try flipping it to make it point upwards. Otherwise try tightening the bolt on top of the stem BEFORE those on the side that clamp it to the steerer tube. This will pack it tighter to the spacers and hopefully eliminate any room for movement.

stevec205gti

Loosen the two clamp bolts at the side of the stem and tighten up the bolt on the top of the stem - this should tighten the headset up. If this doesn't work look to check that the cap on the top isn't bottoming out on the top of the steerer tube

JustRidecp

What Steve said.

Sounds like you need to adjust the pre-load on your headset bearings. A step by step guide to do this can be found here.

Headset Service

Scroll down to "Headset Adjustment - Threadless type.

Hope this helps